Backlight unit and liquid crystal display having the same

ABSTRACT

A backlight unit and a liquid crystal display having the same. The backlight unit includes a lower cover, an interconnection coupling hole, an inverter board, and an interconnection. The lower cover accommodates a printed circuit board, which mounts at least one light emitting diode thereon and is provided at one side thereof with a first connector. The interconnection coupling hole is formed in a bottom surface of the lower cover at a position corresponding to the first connector. The inverter board is disposed on a rear surface of the lower cover to apply a driving voltage to the at least one light emitting diode. The interconnection is provided at one end thereof with a second connector to electrically connect the printed circuit board to the inverter board. A coupling part of the first connector coupled to the second connector is directed to the interconnection coupling hole, so the assembling time of the backlight unit and the liquid crystal display is reduced, thereby improving the productivity of the backlight unit and the liquid crystal display.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of prior application Ser.No. 12/632,894, filed on Dec. 8, 2009 in the United States Patent andTrademark Office, which claims priority under 35 U.S.C. §119 of KoreanPatent Application No. 10-2008-0136259, filed on Dec. 30, 2008, in theKorean Intellectual Property Office, the disclosure of which isincorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present general inventive concept relates to a backlight unit and aliquid crystal display having the same. More particularly, the presentgeneral inventive concept relates to a backlight unit to improveefficiency and reliability through an interconnection structure, whichapplies power to a printed circuit board on which a light emitting diodeis mounted, and a liquid crystal display having the same.

2. Description of the Related Art

A liquid crystal display (LCD) displays images using electrical andoptical properties of liquid crystal. Since the LCD has advantages ofslimness, lightweight, low power consumption, and low driving voltage ascompared with other display apparatuses, the LCD has been extensivelyemployed in various industrial fields.

The LCD includes a liquid crystal display panel, in which liquid crystalis interposed between two transparent substrates and voltage is usablewith the liquid crystal to change a direction of liquid crystalmolecules to optically display images, and a backlight assembly forproviding light to the liquid crystal display panel.

A CCFL (Cold Cathode Fluorescent Lamp), an EEFL (External ElectrodeFluorescent Lamp), and an FFL (Flat Fluorescent Lamp) are used as lightsources of the backlight assembly. However, the CCFL representslimitations in terms of high definition, light weight, slim structureand compact size, so an LED (Light Emitting Diode) has been recentlyused as the light source of the backlight assembly because the LEDrepresents improved performance such as high brightness, long life span,and high color purity. In addition, as restriction on dumping ofdangerous substances, such as mercury, have become widely enforced, theCCFL is less used, and the LED, which is an environmentally friendlydevice, is widely used instead of the CCFL.

The backlight assembly having such an LED as the light source isclassified into a direct-type backlight assembly and an edge-typebacklight assembly according to the arrangement of the LED and the typeof the light guide plate. The direct-type backlight assembly having theLED has a structure in which the LED is disposed in front of thebacklight assembly, so the direct-type backlight assembly has adifficulty in achieving slimness and requires a large number of LEDs,increasing the manufacturing cost.

In contrast, the edge-type backlight assembly has a structure in whichthe LED is mounted at both sides of the backlight assembly and light isintroduced into the front surface of the backlight assembly through alight guide plate, so the edge-type backlight assembly may have athickness smaller than that of the direct-type backlight assembly,thereby realizing the slimness structure.

A backlight unit provided with the LED includes a box-shape bottomchassis having an open upper surface to sequentially receive areflection plate, the light guide plate, and optical sheets therein. Inaddition, a plurality of LEDs mounted on the printed circuit board areprovided adjacent to a side of the light guide plate in the backlightunit.

The LEDs are connected to an inverter board, which is mounted on a rearsurface of the bottom chassis, through a wire or an interconnection toreceive drive voltage, so the LEDs emit light.

In general, the printed circuit board, on which the LEDs are mounted, isconnected to the interconnection inside the bottom chassis, so extraspace for such a connection is required. In addition, when the backlightassembly is coupled to the bottom chassis, short circuit or groundfailure of the interconnection connected to the printed circuit boardmay occur. In this case, the backlight assembly needs to be separatedfrom the bottom chassis and then connected to the bottom chassis again.Accordingly, the assembling work is complicated and the working time isincreased.

SUMMARY

Accordingly, it is a feature of the present general inventive concept toprovide a backlight unit, capable of improving assembling efficiency andreliability of the liquid crystal display, and a liquid crystal displayhaving the same.

Additional features and/or advantages of the present general inventiveconcept will be set forth in part in the description which follows and,in part, will be apparent from the description, or may be learned bypractice of the general inventive concept.

Embodiments of an exemplary embodiment of the present general inventiveconceptare achieved by providing a backlight unit. The backlight unitmay include a lower cover, an interconnection hole, an inverter board,and an interconnection. The lower cover may accommodate a printedcircuit board, which mounts at least one light emitting diode thereonand is provided at one side thereof with a first connector. Theinterconnection coupling hole is formed in a bottom surface of the lowercover at a position corresponding to the first connector. The inverterboard is disposed on a rear surface of the lower cover to apply adriving voltage to the at least one light emitting diode. Theinterconnection may be provided at one end thereof with a secondconnector to electrically connect the printed circuit board to theinverter board. A coupling part of the first connector coupled to thesecond connector may be directed to the interconnection coupling hole.

The second connector is coupled to the first connector through theinterconnection coupling hole.

The first connector may be provided in a socket type and the secondconnector may be provided in a plug type.

The printed circuit board is fixed to a fixing member, which is providedon the lower cover and may include thermal conductive metal.

The coupling part of the first connector protrudes through theinterconnection coupling hole.

Embodiments of another exemplary embodiment of the present generalinventive concept provide a backlight unit. The backlight unit mayinclude a light guide plate, a printed circuit board, a lower cover, andan inverter board. At least one light emitting diode radiating light toone side surface of the light guide plate is mounted on the printedcircuit board. The lower cover accommodates the light guide plate andthe printed circuit board therein. The inverter board is disposed at arear surface of the lower cover to apply a driving voltage to the lightemitting diode. An interconnection coupling hole may be formed at oneside of a bottom surface of the lower cover, and an interconnection forelectrical connection between the printed circuit board and the inverterboard passes through the interconnection coupling hole to connect theprinted circuit board to the inverter board.

A plug-type connector may be provided at one end of the interconnectionconnected to the printed circuit board, and a socket-type connectorhaving a coupling part, into which the plug type connector is inserted,may be provided on the printed circuit board.

The interconnection coupling hole is formed at a position correspondingto the plug type connector, and the coupling part is directed to theinterconnection coupling hole.

Embodiments of another exemplary embodiment of the present generalinventive concept provides a liquid crystal display. The liquid crystaldisplay includes a liquid crystal display panel, a backlight unit, alower cover, an inverter board and an interconnection. The backlightunit includes a light guide plate to provide light to the liquid crystaldisplay panel and a printed circuit board, on which a plurality of lightemitting diodes are mounted to radiate light toward the light guideplate and a first connector is provided at one side of the printedcircuit board. The lower cover may accommodate the liquid crystaldisplay panel and the backlight unit, and has an interconnectioninstallation hole formed at a position corresponding to the firstconnector.

The inverter board may be installed on a rear surface of the lower coverto apply a driving voltage to the light emitting diodes. Theinterconnection has one end, which may be connected to the inverterboard, and an opposite end, which may be connected to the firstconnector through the interconnection installation hole.

A coupling part of the first connector coupled to the second connectoris directed to the interconnection installation hole.

The first connector may be provided in a socket type and the secondconnector may be provided in a plug type.

The coupling part of the first connector may protrude from the rearsurface of the lower cover through the interconnection installationhole.

A fixing member including thermal conductive metal may be provided onthe lower cover to fix the printed circuit board.

As described above, according to the backlight unit and the liquidcrystal display having the same of the disclosure, the printed circuitboard may be easily connected to the inverter board, and theinterconnection may be prevented from being broken during assemblingwork, thereby reducing the assembling time. Accordingly, theproductivity and reliability of the liquid crystal display can beimproved.

Embodiments of the present general inventive concept also provide for animage display apparatus, comprising a panel disposed in a direction todisplay an image, a light guide plate disposed in a direction to guidelight in a second direction towards the panel, a printed circuit boardhaving one or more light emitting diodes disposed to emit light in thedirection, a lower cover mounted with a power unit disposed opposite tothe light guide plate with respect to the lower cover, and a hole formedon the lower cover to connect the printed circuit board and the powerunit.

Embodiments of the present general inventive concept also provide for animage display apparatus, comprising an upper cover and lower cover, apanel disposed between the upper cover and the lower cover, an opticalfilm disposed between the panel and the lower cover, a light guide platedisposed between the optical film and the lower cover, a power unitdisposed on the lower cover opposite to the guide plate, a printedcircuit board having one or more light emitting diodes, and disposed toface a side of the light guide plate, a connector mounted on the printedcircuit board and connected to the one or more light emitting diodes, ahole formed on the lower cover to correspond to the connector, and aninterconnection disposed in the hole to connect the power unit to theconnector.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other features and utilities of the present generalinventive concept will become apparent and more readily appreciated fromthe following description of the embodiments, taken in conjunction withthe accompanying drawings, in which:

FIG. 1 is an exploded perspective view showing a liquid crystal displayaccording to an exemplary embodiment of the present general inventiveconcept;

FIG. 2 is a perspective view showing a part of the liquid crystaldisplay of FIG. 1;

FIG. 3 is a perspective view showing a rear surface of a lower cover ofthe liquid crystal display according to the exemplary embodiment of thepresent general inventive concept;

FIG. 4 is a sectional view showing the liquid crystal display accordingto the exemplary embodiment of the present general inventive concept;and

FIG. 5 is a sectional view showing a liquid crystal display according toanother exemplary embodiment of the present general inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentgeneral inventive concept, examples of which are illustrated in theaccompanying drawings, wherein like reference numerals refer to the likeelements throughout. The embodiments are described below to explain thepresent general inventive concept by referring to the figures

As illustrated in FIG. 1, a liquid crystal display according to anexemplary embodiment of the present general inventive concept includes aliquid crystal display panel 20 and a backlight unit 40 disposed at arear surface of the liquid crystal display panel 20.

The liquid crystal display panel 20 and the backlight unit 40 areaccommodated between an upper cover 10 and a lower cover 80.

That is, the liquid crystal display panel 20 is mounted on a mold frame30, and may be fixed on the backlight unit 40 by the upper cover 10,which is coupled to the backlight unit 40.

The upper cover 10 may be coupled to the lower cover 80 through a hookstructure or a fastening member such as a screw.

The liquid crystal display panel 20 includes a thin film transistorsubstrate 21, on which a thin film transistor may be formed, a colorfilter substrate 27 facing the thin film transistor substrate 21 and aliquid crystal layer (not illustrated) provided between the thin filmtransistor 21 and the color filter substrate 27.

A driver 22 is provided at a side of the thin film transistor substrate21 to apply a driving signal.

The driver 22 may include an FPC (Flexible Printed Circuit) 23, adriving chip 24 mounted on the FPC 23, and a PCB (Printed Circuit Board)25 connected to one side of the FPC.

Although the driver 22 according to the exemplary embodiment is providedthrough a COF (Chip On Film) scheme, the disclosure is not limitedthereto. According to another exemplary embodiment, the driver can beprovided through a TCP (Tape Carrier Package) scheme or a COG (Chip OnGlass) scheme, which are generally known in the art. In addition,according to another exemplary embodiment of the present generalinventive concept, the driver 22 may be mounted on the thin filmtransistor substrate 21.

Such a liquid crystal display panel 20 forms an image by adjusting analignment of the liquid crystal layer. However, the liquid crystaldisplay panel 20 is a non-emissive device, so the liquid crystal displaypanel 20 requires light provided from the backlight unit 40 disposed atthe rear surface of the liquid crystal display panel 20.

The backlight unit 40 may include a plurality of optical films 50disposed at the rear surface of the liquid crystal display panel 20, alight guide plate 60 disposed at a rear surface of the optical films 50,a light source unit 70 disposed along both opposite sides of the lightguide plate 60, and a reflection plate 41 disposed below the light guideplate 60.

The optical films 50 disposed at the rear surface of the liquid crystaldisplay panel 20 may include a protection film 51, a prism film 53, anda diffusion film 55.

The diffusion film 55 may be provided with a base plate and a coatinglayer, which is formed on the base plate in a bead pattern such thatlight from the light source unit 70 can be diffused and then provided tothe liquid crystal display panel 20.

The prism film 53 is provided at an upper surface thereof withtriangular prisms regularly arranged such that light diffused by thediffusion film 55 is collected vertically to a plane of the liquidcrystal display panel 20 disposed above the prism film 53. In general,two prism films 53 may be used, and micro prisms of each prism film 53form a predetermined angle with each other. Most light passing throughthe prism film 53 travel vertically, thereby providing uniform lightbrightness.

The protection film 51 may be disposed on the prism film 53 to protectthe prism film 53, which is sensitive to scratch or dust.

The light guide plate 60 includes acryl based resin, such aspolymethylmethacrylate, or polymethylstyrene (copolymer ofmethylmethacrylate and stylene). The light guide plate 60 uniformlyguides light from the light source unit 70 to the diffusion film 55.

The light source unit 70 may include a plurality of light emittingdiodes 71 to generate light, a printed circuit board 73 on which thelight emitting diodes 71 are mounted, and a first connector 74, which isformed at one side of the printed circuit board 73 and is connected tothe light emitting diodes 71 to provide power to the light emittingdiodes 71.

The light emitting diodes 71 may include a plurality of white lightemitting diodes to emit white light, or may be provided in a combinationof light emitting diodes to emit red light, green light, and blue light,respectively.

The printed circuit board 73 may be provided in the form of a metal PCB(Printed Circuit Board) including a silicon steel plate, a galvanizedsteel plate, or an aluminum disk which has superior thermalconductivity.

The printed circuit board 73 provides the driving signal to the lightemitting diode 71 and emits heat generated from the light emittingdiodes 71 to the outside.

Such a light source unit 70 may be installed at a position adjacent tothe side of the light guide plate 60 to radiate light to the side of thelight emitting plate 60. The light introduced to the side of the lightguide plate 60 is transferred to the optical films 50 mounted on thelight guide plate 60.

Although the light source unit 70 according to the exemplary embodimentof the present general inventive concept may be disposed around thelight guide plate 60 adjacent to sides of the light guide plate 60, thedisclosure is not limited thereto. According to another exemplaryembodiment of the present general inventive concept, the light sourceunit 70 may be disposed at one side of the light guide plate 60 or maybe disposed at two opposite sides of the light guide plate 60.

The reflection plate 41 is disposed below the light guide plate 60 suchthat light directed downward through the light guide plate 60 isreflected to the light guide plate 60. A reflection plate slit 42 isformed in the reflection plate 41 at a position corresponding to afixing protrusion 82 such that the fixing protrusion 82 is inserted intothe slit 65, wherein the fixing protrusion 82 formed on the bottomsurface 81 of the lower cover 80 to fix the reflection plate 41 to thelower cover 80.

The reflection plate 41 may include plastic such as PET(polyethyleneterephthalate) or PC (polycarbonate).

The light guide plate 60, light source unit 70, and reflection plate 41are accommodated in the lower cover 80, which accommodates the moldframe 30 and is coupled to the upper cover 10.

Hereinafter, the light guide plate and the light source unitaccommodated in the lower cover will be described with reference toFIGS. 2 and 3.

FIG. 2 is a perspective view showing a part of the liquid crystaldisplay of FIG. 1, and FIG. 3 is a perspective view schematicallyshowing a rear surface of the lower cover of the liquid crystal displayaccording to the exemplary embodiment of the present general inventiveconcept.

Referring to FIG. 2, the light guide plate 60 accommodated in the lowercover 80 may be provided in a rectangular shape having a predeterminedthickness and faces the light source unit 70. The light guide plate 60includes an incident surface 61 to receive light emitted from the lightsource unit 70, an exit surface 63 to discharge light introduced throughthe incident surface 61, and a reflection surface (not illustrated)facing the exit surface 63.

The lower cover 80 may be provided in a box shape having an open upperpart. Such a lower cover 80 includes a bottom surface 81, on which thelight guide plate 60 is mounted, and a sidewall 85 extending upward fromthe edge of the bottom surface 81 such that the light guide plate 60 andthe light source unit 70 are fixedly accommodated within the sidewall85.

A fixing protrusion 82 is formed on the bottom surface 81 of the lowercover 80 to fix the light guide plate 60 to the lower cover 80. A slit65 is formed in the light guide plate 60 at a position corresponding tothe fixing protrusion 82 such that the fixing protrusion 82 is insertedinto the slit 65. A1 illustrates the distance between slit 65 and theend of the side edge of the light guide plate 60 which slit 65 opens upthereto. A2 illustrates the distance between fixing protrusion 82 and anend of a side edge of the bottom surface of the lower cover 80.

Therefore, when the light guide plate 60 is accommodated in the lowercover 80, the fixing protrusion 82 is inserted into the slit 65, so themovement of the light guide plate 60 is restricted.

Meanwhile, a fixing member 83 to install the light source unit 70 isprovided at a position spaced apart from the sidewall 85 of the lowercover 80 to fix the light source unit 70 provided at a position adjacentto the incident surface 61.

The fixing member 83 faces the incident surface 61 of the light guideplate 60, and may include metal having superior thermal conductivity.Thus, heat generated from the light emitting diode 71 is transferred tothe lower cover 80 through the fixing member 83 and then is dischargedto the outside.

In addition, the fixing member 83 may be formed by fixing an extrusionmember including aluminum to the lower cover 80. Otherwise, the fixingmember 83 may be integrally formed with the lower cover 80.

The printed circuit board 73 of the light source unit 70 may be fixed tothe fixing member 83 through a fastening member such as a screw or anadhesion member. Therefore, the light emitting diode 71 mounted on theprinted circuit board 73 emits light toward the incident surface 61 ofthe light guide plate 60.

Although the light source unit 70 according to the exemplary embodimentof the present general inventive concept is installed on the fixingmember 83, the disclosure is not limited thereto. According to anotherexemplary embodiment of the present general inventive concept, the lightsource unit 70 may be installed on the sidewall 85 of the lower cover80.

The first connector 74 provided in a socket type may be installed at oneend of the printed circuit board 73 to provide power to the lightemitting diode 71.

A coupling part 75 (see FIG. 4) of the first connector 74 is directed tothe bottom surface 81 of the lower cover 80. An interconnection couplinghole 84 is formed in the bottom surface 81 of the lower cover 80 at aposition corresponding to the coupling part 75 of the first connector74. The coupling part 75 refers to a part at which the first connector74 is coupled to a second connector 92, which will be described later.That is, the coupling part 75 may be directed in a second directioncrossing a first direction parallel with the bottom surface 81 of thelower cover 80. The second direction crossing the first direction may beperpendicular to the bottom surface 81 of the lower cover 80, but is notlimited thereto.

Referring to FIG. 3, a power unit 300 is mounted on to the lower cover80. The power unit 300 includes an inverter board 90, a second connector92, an interconnection 91, and a second connector 92. The inverter board90 and a PCB may be installed on the rear surface 86 of the lower cover80. The inverter board 90 transforms external power such that theexternal power has a predetermined voltage level and then provides thetransformed power to the light emitting diode 71. The PCB may convert ananalog data signal into a digital data signal and provides the digitaldata signal to the liquid crystal display panel 20.

The inverter board 90 is connected to the light source unit 70 throughan interconnection 91. The second connector 92 provided in a plug typemay be installed at both ends of the interconnection 91.

Thus, one end of the interconnection 91 is connected to a connectormounted on the inverter board 90 and the remaining end of theinterconnection 91 is connected to the socket type first connector 74provided on the printed circuit board 73 through the interconnectioncoupling hole 84.

In general, the connectors 74 and 92 are connected to each other toprovide electric connection. The plug type second connector 92 has acoupling protrusion, and the socket type first connector 74 has acoupling groove into which the coupling protrusion is inserted.Accordingly, if the coupling protrusion of the second connector 92 isinserted into the coupling groove of the first connector 74, theinterconnection is electrically connected.

Although the exemplary embodiment of the present general inventiveconcept has been described wherein the socket type first connector 74 isinstalled on the printed circuit board 73 and the plug type secondconnector 73 is installed at the end of the interconnection 91, thisdescription is for illustrative purposes only. According to anotherexemplary embodiment of the present general inventive concept, a plugtype first connector may be installed on the printed circuit board 73and a socket type second connector may be installed at the end of theinterconnection 91.

In addition, the coupling part 75 of the first connector 74 installed onthe printed circuit board 73 may be provided inside the lower cover 80.Otherwise, as illustrated in FIG. 5, the coupling part 75 of the firstconnector 74 may protrude out of the rear surface 86 of the lower cover80.

Hereinafter, the assembling structure and operation of the liquidcrystal display according to the exemplary embodiment of the presentgeneral inventive concept will be described with reference to FIG. 4.FIG. 4 is a sectional view showing the liquid crystal display accordingto the exemplary embodiment of the present general inventive concept.

First, the light source unit 70 is fixed to the fixing member 83provided in the lower cover 80. In a state that the light source unit 70is fixed to the fixing member 83, the coupling part 75 of the firstconnector 74 installed at the end of the printed circuit board 73 facesthe bottom surface 81 of the lower cover 80, and the interconnectioncoupling hole 84 of the lower cover 80 is provided at a positioncorresponding to the coupling part 75 of the first connector 74.

After that, the backlight unit 40 is accommodated in a space formed inthe sidewall 85 of the lower cover 80. In detail, the reflection plate41 is mounted on the bottom surface 81 of the lower cover 80, the lightguide plate 60 is mounted on an upper surface of the reflection plate41, and the optical films 50 are mounted on the upper surface of thelight guide plate 60.

The mold frame 30 is mounted on the backlight unit 40. The mold frame 30is coupled to the lower cover 80 while supporting the edge of the lightsource unit 70, the light guide plate 60 and the optical films 50.Accordingly, the movement of the backlight unit 40 is restricted.

The liquid crystal display panel 20 is mounted on the mold frame 30. Asthe upper cover 10, which surrounds the edge of the upper surface of theliquid crystal display panel 20, is coupled to the sidewall 85 of thelower cover 80, the liquid crystal display panel 20 is fixed above thebacklight unit 40.

After the liquid crystal display has been assembled, the plug typesecond connector 92, which may be formed at the end of theinterconnection 91 connected to the inverter board 90, passes throughthe interconnection coupling hole 84 and then is coupled to the sockettype first connector 92 installed on the printed circuit board 73.

Accordingly, the light source unit 70 is electrically connected to theinverter board 90 through the interconnection 91, so driving voltage maybe transferred from the inverter board 90 to the light emitting diode71.

Therefore, the interconnection 91, which is provided to connect theprinted circuit board 73 having the light emitting diode 73 to theinverter board 90, passes through the interconnection coupling hole 84and then is coupled to the inverter board 90 along the rear surface ofthe lower cover 80. As a result, the first and second connectors 74 and92 may be prevented from being separated from each other when the liquidcrystal display is assembled, so reliability of the liquid crystaldisplay can be improved and the assembling process can be effectivelyperformed.

In addition, the first connector 74 provided at one side of the printedcircuit board 73 may be connected to the interconnection 91 at the rearsurface 86 of the lower cover 80, so an additional space to connect theinterconnection is not required inside the lower cover 80.

Further, as illustrated in FIG. 5, if the coupling part 75 of the firstconnector 74 protrudes from the rear surface 86 of the lower cover 80,the first connector 74 can be more easily connected to the secondconnector 92.

Although few embodiments of the present general inventive concept havebeen illustrated and described, it would be appreciated by those skilledin the art that changes may be made in these exemplary embodimentswithout departing from the principles and spirit of the present generalinventive concept, the scope of which is defined in the claims and theirequivalents.

What is claimed is:
 1. An edge-type backlight unit, comprising: a lightunit comprising: a printed circuit board having a plurality of lightemitting diodes (LEDs) mounted on the printed circuit board; and a firstconnector formed at one side of the printed circuit board; a light guideplate having an incident surface to receive light from the plurality ofLEDs; a lower cover provided with a bottom surface on which the lightguide plate is accommodated, an interconnection coupling hole beingformed through the bottom surface; a board disposed on a rear side ofthe lower cover, and configured to apply a driving voltage to theplurality of LEDs; and wherein: the first connector is provided with acoupling part; and the coupling part is adapted to face in a directiondifferent from a longitudinal direction of the printed circuit board. 2.The edge-type backlight unit of claim 1, wherein the coupling part isdirected to the interconnection coupling hole formed through the bottomsurface of the lower cover.
 3. The edge-type backlight unit of claim 1,further comprising: an interconnection having a second connectorprovided at an end thereof to electrically connect the printed circuitboard to the board, wherein the interconnection coupling hole isconfigured to allow at least one of the first connector and the secondconnector to pass through the interconnection coupling hole.
 4. Theedge-type backlight unit of claim 1, wherein the first connectorprotrudes from the rear side of the lower cover through theinterconnection coupling hole.
 5. The edge-type backlight unit of claim1, wherein the plurality of LEDs is mounted along the longitudinaldirection of the printed circuit board.
 6. The edge-type backlight unitof claim 1, wherein the first connector and the plurality of LEDs areformed on the same side of the printed circuit board.
 7. The edge-typebacklight unit of claim 2, wherein the interconnection coupling hole isformed at a position corresponding to the first connector, and thecoupling part of the first connector is disposed to face theinterconnection coupling hole.
 8. The edge-type backlight unit of claim1, wherein the coupling part is directed in an outward direction of thebottom surface of the lower cover.
 9. The edge-type backlight unit ofclaim 1, wherein the printed circuit board is fixed to a fixing member,the fixing member being provided on the lower cover and includingthermally conductive metal.
 10. The edge-type backlight unit of claim 3,wherein: the interconnection passes through the interconnection couplinghole and is extended toward the first connector; and the secondconnector is coupled to the coupling part of the first connector in adirection perpendicular to the bottom surface of the lower cover. 11.The edge-type backlight unit of claim 3, wherein the second connector iscoupled to the first connector via the interconnection coupling hole.12. The edge-type backlight unit of claim 3, wherein: the firstconnector is a socket type first connector installed on the printedcircuit board; and the second connector is a plug type second connectorinstalled at an end of the interconnection.
 13. The edge-type backlightunit of claim 3, wherein: the first connector is a plug type firstconnector installed on the printed circuit board; and the secondconnector is a socket type second connector installed at an end of theinterconnection.
 14. The edge-type backlight unit of claim 3, whereinthe coupling part is disposed at an inside of the lower cover andcouples the first connector to the second connector.
 15. A liquidcrystal display comprising an edge-type backlight unit according toclaim 1.